Phonograph tone arm mounting



June 18, 1946. c. B. DALE PHONOGRAPH TONE ARM MOUNTING 2 Sheets-Sheet 1Filed Aug. 30, 1945 June 18, 1946.

c. B. DALE PHONOGRAPH TONE ARM MOUNTING Filed Aug. 30, 1943 2Sheets-Sheet 2 will!!! v v v r v r z 1/ A Patented June 18, 1946PHONOGRAPH TONE ARM MOUNTING Colin B. Dale, Oak Park, Ill., assignor toWebster- Chicago tion of Illinois Corporation,

Chicago, 11]., a corpora- Application August 30, 1943, Serial No.500,483

, 1 This invention is directed to the means provided for mounting aphonograph tone arm in such a way as' to permit it to swing inwardlyunder the guidance of the needle which engages the record groove of a,disk without appreciable restraint due to friction in the bearing whichsupports the shaft upon which the tone arm is pivoted. This result isattained by employing but a single point bearing for the lower end ofthe shaft which is subjected to a direct vertical thrust under theweight of the tone arm, so that, while playing, side bearing pressuresare eliminated together with all friction or cramping occasionedthereby. This method of support not onl avoids wear on the parts andsimplifies the construction, but also prevent mechanical noises in thetone reproduction and reduces wear on the record line.

Further objects and details will appear from a description of theinvention in conjunction with the accompanying drawings wherein:

Figure 1 is a sectional detail showing those portions of a recordchanging phonograph which relate to the construction andoperation of thepresent invention; and

Figs. 2, 3, 4 and 5 are sectional details showing the tone arm and itsstages of adjustment, 1

The tone arm with its mountings and associated mechanisms is here shownas embodied in the structure of a record changing phonograph which isthe subject or a patent application filed of even date herewith, but itwill be understood that the present invention is capable of generalemployment in connection with phonographs, and that its use is in no wayconditioned by the presence or absence of record changing features or ofspecial mechanisms employed for imparting rotation to the turntable, orother features not having special relation to the tone arm and itsmountings. It will therefore be understood that any disclosure of suchadditional features serves merely to illustrate one type of phonographwith which the present invention may be advantagecusly employed, and isnot to be regarded as a limitation on the more general use to which theinvention is adapted. I

As shown, the tone arm it is in the form of an elongated channel-shapedstamping having side flanges ii, an inner end wall I2, and an outer endwall It, The inner end houses the mounting for a needle It which may beof any conventional type, or which may have connection with a radioamplifier or equivalent construction.

mountings in successive 8 Claims. (Cl. 274-423) The needle features arestandard and need not be described in further detail.

The tone arm near its outerend has secured to its under facea bracket lhaving depending cars It which carry a horizontal pintle l1 upon whichthe ears are pivoted, so that the tone arm will have freedom of pivotalmovement in a vertical plane but must swing laterally in unison with themounting bracket l8. Themounting bracket is fixed upon the upper buttend of a Vertical shaft I 9 which is supported through aligned guideapertures and 2!, respectively, in the top wall 22 of a standard 23 andin a base plate 24 to which the standard is affixed. The standard hasside walls 25 and an upstanding tongue 26 termihating in a stop flange2'! which coacts with a hooked finger 28 depending from the tone armnear its outer end and beyond thepintle on which the arm is pivoted. Theconnection between the hooked finger and the stop during various stagesin the lifting of the pivoted end of the tone arm is i lustrated inFigs. 2, 3, 4 and 5.

The lower end 29 of the vertical tone arm shaft is of pointed or conicalformation, and is supported in thrust bearing contact upon the outer end30 of a lever 3! fulcrumed at 32 upon a hanger 33 depending from thebase plate. The inner end of the lever is upturned and carries a roller33 which engages a cam track 34 on the lower face of a cam disk 35journaled upon a stub shaft 36 depending from the base plate. The, camtrack has formed therein a notch 31 which is normally in register withthe roller 33 duringthe playing of a record while the thrust of a spring38 holds the outer end of the lever in lowered position and with it thetone arm shaft which lowers the hooked finger 28 sufficiently to breakengagement with the stop flange 21; This is the position shown in Fig. 1wherein the tone arm is free to follow the record line while supportedonly by the needle at its inner end, and by the vertical shaft with itscone bearing near its outer end. The thrust on the shaft is directlydownward so that no side pressure is exerted against the sides of theapertures 20 and 2! which thus serve merely as guides to position andsteady the shaft without serving in any true sense as bearings, so thatfrictional contact therewith is negligible.

The periphery of the cam disk is provided with spur teeth 39 which,while in train with a pinion 40 on the constantly rotating spindle 4tupstanding from the center of the turntable 42, will impart a singlerotation to the cam disk to elevat/e the tone arm in preparation for itsoutward acoaieo swing to afi'ord clearance for the positioning of arecord disk, and the clearance will he maintained during the inswing ofthe tone a until the needleengages the low pitched record groove.

The outswinging of the tone arm may be per formed manually orautomatically, as described in the companion application aforesaid, orin any other desirable or convenient manner, and it is not deemednecessary to here describe such ice.- tures, which form no essentialpart of the present invention; The same is true as regards the meansprovided for constantly rotating the turnm cle with its spindle, themeans for automatically releasing record disks when such means are comployed, the means for temporarily entraining the cam dish with theconstantly rotating pinion on the turntable spindle during the recordchanging operations and other associated operations, all of which may beperformed automatically in timed sequence as set forth in the companionapplica= tion aforesaid, but are not required when single records aremanually positioned and removed.

Operation of the lever, which may be manually operated or controlled byautomatic means of any suitable character.

When it becomes necessary to change record disks the lever, or otherequivalent means, will be shifted to elevate the tone arm shaft whichthus imparts a thrust against the outer end or the tone arm whichlorings the linger into engagement with the fixed stop 2i (as in Fig. 3)so that a. continuing upward thrust will elevate the inner free end ofthe tone arm to the position shown in Fig. i, thereby affordingclearance for the removal of a played record and the positioning of anew one.' It will be seen that it is only during the record changinginterval that the tone arm is in any way restrained inits free swingingmovements, and that during the playing interval it is free to follow therecord line without any restraint due to friction or cramping in thetone arm mountings.

Although the invention has been described with particularity, it will heunderstood that various modifications in detail may be made withoutdeparting from the spirit of the invention.

I claim:

1. in a tone arm mounting, in combination with a turntable, a tone armadap to carry a needle at its inner end, a vertical tone arm shaft,connections between the outer end portion of the tone arm and the shaftadapted to permit pivotal movement of the tone arm in a vertical planeand to impart a vertical thrust upon the shaft, a vertically adjustablesupport for the lower end of the shaft afiording a tt hearing therefor,a member contacting the side of the shaft in a manner free irom hearingthrusts and adopted to steady the shaft and maintain it in verticalposition and means for restraining the outer end of the tone arm beyondthe aforesaid connections, and adapted to cause an angular uplift of theinner end or the tone when the verti short u raised. 1

low level to permit the.

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point thrust hearing therefor, a member contactingthe side of the shaftin a manner free from hearing thrusts and adapted to steady the shaftand maintain it in vertical position and means for restraining the outerend oi the tone arm beyond the aforesaid connections, and adapted tocause an angular uplift of the inner end or the tone arm when thevertical shaft is raised.

3. In a tone arm mounting, in combination with a turntable, a tone armadapted to carry a needle at its inner end, a vertical tone arm shaft,connections between the outer end portion oi the tone arm and the shortadapted to permit pivotal movement of the tone arm in a vertical planeand to impart a vertical thrust upon the shaft, a vertically adjustablesupport for the lower end of the shaft afiording a thrust hearingtherefor, a member contacting'the side oi the shaft in a manner freefrom hearing thrusts and adapted to steady the shaft and maintain it invertical position, a stop memher on the outer end of the tone arm beyondits point of support on the shaft, and a fined stop member in adjacentrelation thereto and adapted to engage the tone arm stop member duringthe liiting of the shalt to restrain the outer end of the tone arm whilecontinuing upward movement of the shaft liftsthe free inner end of thetone arm.

4.111 a tone arm mounting, in combination with a turntable, a tone armadapted to carry a needle at its inner end, averticsl tone arm shaft,connections between the outer end portion of the tone arm and the shaftadapted to permit pivotal movement oi the tone arm in a vertical planeand to impart a vertical thrustupon the shaft, a vertically adjustablesupport tor the lower end of theshait afi'ording 0. single conical pointthrust hearing therefor, a member con tacting the side of? the shaft ina manner free from hearing thrusts and adapted to steady the shaft andmaintain it in vertical position, a stop memher on the outer end oi thetone arm beyond its point oi support on the shaft, and a hired stopmember in adjacent reletionthereto and adapted to engage the tone armstop member during the lifting of the-short to restrain the outer end oithe tone arm while continuing upward movement oi the shaft lifts thefree inner end of the tone arm.

5. In a tone arm mounting, in combination with a turntable, a tone armadapted to carry a needle at its inner end, a vertical adjustable tonearm shaft and a member aflording lateral non-frictional guiding contacttherewith during vertical adjustment, bracket connections between theouter end portion of the tone arm and the shaft including a horizontallydisposed pintle upon which the tone arm is pivoted near its outer end topermit movement in a vertical plane, said mountings being adapted toimpart a vertical thrust upon the shaft, a lever one end of whichoflords a single conical point thrust bearing for the lower end of theshaft, 9. hooked stop linger depending from the outer end oi the tonearm beyond its pivotal mounting, and a fined stop member in adjacentrelation thereto and adapted to engage the stop finger during thelifting of the shaft to restrain the outer end of the tone arm whilecontinuing upward movement oi the shaft lifts the free inner end of thetone arm.

6. A tone arm mounting for phonographs and the like including a fixedsupport member, a spindle extending vertically therethrough, a tone armadapted to carry a needle at its inner end and at its outer endsupportedduring play solely by pivot means having a generally horizontal axisapproximately intersecting the axis of the spindle whereby the weight ofthe tone arm car ried by the pivotal support member during play isreceived by the spindle as an axial thrust, tilt means disposed toengage the tone arm at a point spaced from the axis of the spindle andfrom the inner end of the tone arm, and means to produce relative motionbetween the spindle and the tilt means in a direction axial of thespindle to raise the inner end of the tone arm from a record.

7. A tone arm mounting for phonographs and g the like including a fixedsupport member, a

spindle extending vertically therethrough, a tone arm adapted to carry aneedle at its inner end and at its outer end supported during playsolely by' pivot means having a generally horizontal axis approximatelyintersecting the axis of the spindle whereby the weight of the tone armcarried by the pivotal support member during play is received by thespindle as an axial thrust, and means spaced from said pivotal supporteilective upon axial movement of the spindle for restraining the tonearm to cause a tilting action of the tone, arm about the. pivotalsupport.

8. A tone arm mounting including a rigid supporting member, a spindlemounted thereon for axial movement and for rotation about a generallyvertical axis, generally horizontal pivot means carried by the spindleand adapted to pivotally support the outer end of a tone arm therefromand restraining means carried by the rigid support and adapted torestrain the tone arm at a point more remote from the axis of thespindle than the horizontal pivot means to cause a tilting of the tonearm upon axial movement of the spindle, the outer end of the tone ambeing supported during play solely by said pivot means.

COLIN B; DALE.

